Centering-punch



H. M. WALKER. CENTERING PU'N']CH. APPLICATION HLED Nov.29, 1919.

1,351,592, Patented Aug. 31, 1920.

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HARRY M. WALKER, OF ELLENTON, SOUTH CAROLINA.

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Specification of Letters Patent.

Patented Aug. 31, 1920.

Application filed November 29, 1919. Serial No. 341,555.

To all whom it may concern.

Be it known that I, HARRY M. WVALKER, a citizen of the United States,and a resident of Ellenton, in the county of Aiken and tate of SouthCarolina, have invented cer tain new and useful Improvements inCentering-Punches, of which the following is a specification.

My invention is an improvement in centering punches, and has for itsobject to provide a device of thecharacter specified, having means inconnection therewith for permitting the punch to be accurately centeredin an opening-of a pattern plate for instance, to insure that the punchwill engage the work at the exact center of the opening desired to bemade, and wherein the punch is adjustable for openings of vari ous size.

In the drawings Figure 1 is a front view of the improved punch in use,

Fig. 2 is a vertical section,

Fig. 3 is a section on the line 3-3 of Fig. 2,

Fig. 4 is a perspective view of one of the centering blades.

The improved punch comprises a body 1 of cylindrical form, having itslower end pointed as shown at 2, and this body is provided intermediateits ends with a series of longitudinally extending grooves 3, threegrooves being provided in the present instance, and the said grooves arespaced apart from each other at intervals of 120.

A centering blade 4 is pivoted in each groove, by means of a pivot pin 5which passes through registering openings in the side walls of thegroove and in the blade, and each blade at its upper end is normallypressed away from the body of the punch by means of a plate spring 6.Each of these springs 6 is secured to the blade at its top, and has anangular portion at its free end which bears against the bottom of thegroove.

Each blade is of angular formation, as clearly shown in Figs. 2 and 4,comprising a relatively long portion and a relatively short portionextending at an obtuse angle with respect to each other, and the freeend of the short portion is bent outwardly as shown at 7 to provide anengaging surface for engaging the inner wall of the opening 8 of thepattern 9.

A collar 10 encircles the body at the pivotal connection of the blades,it being understood that all the blades are pivoted at the same point inthe length of the body, and this collar is movable on the body, to causethe lower ends of the blades to project more or less beyond theperiphery of the centering punch. The upper end of the punch, that is,the end remote from the point 2 is formed into a head 11 as shown, forengagement by a hammer or the like to cause the punch to mark the workindicated at 18.

The collar 10 as shown more particularly inFig. 3 has a notch or recess12 at each blade, in which a portion of the blade fits, and angularmovement of the collar is thus prevented. The blades are so formed thatwhen the spring 6 is fully expanded, the lower end of the blade, thatis, that portion below the pivotal connection will lie close in thegroove.

In operation the pattern 9 which may be of course the work which hasalready been punched, is laid upon the work 13 to be punched, andproperly positioned thereon. Now the punch is inserted in one of theopenings 8 of the pattern, and properly centered by means of the blades4:, the said blades being moved inward or outward until the lower endthereof contacts smoothly with the inner wall of the opening 8.

They may be moved simultaneously by means of the collar 10. It will beevident that when the collar is moved upwardly above the points of theblades, the lower ends of the blades will be extended, while when thecollar is moved downwardly, the said lower ends will be retracted. Whenthe punch isproperly centered, a blow from a hammer or the like on thehead ofthe punch will make the centering opening. Only a light blow ofthe hammer is necessary.

I claim 1. A centering ,punch comprising a body having at one end apoint and at the other a head, and having longitudinally extendinggrooves spaced apart from each other, a blade of angular formationpivoted 1n each groove, each blade consisting of a relatively longportion and a relatively short portion extending at an obtuse angle withrespect to each other, said short portions extending toward the engagingend of the punch, a spring normally pressing the long portion of eachblade away from the body, collar movable on the body and the blades foroperating the blades.

2. A centering punch comprising a body having longitudinally extendinggrooves spaced apart from each other, a blade of angular formationpivoted in each groove, each blade consisting of a relatively longportion and a relatively short portion extending at an obtuse angle withrespect to each other, said short portions extending toward the engagingend of the punch, a spring normally pressing the long portion of eachblade away from the body, and a collar movable on the body and theblades for operating the blades.

8. A centering punch provided with longitudinally extending groovesspaced apart from each other, a centering blade arranged in each grooveand pivoted to the punch, each blade being of angular formation andpivoted at the angle thereof, and means for simultaneously swinging theblades on their pivotal connection, said means comprising ing theblades, springs normally acting on the blades to swing the ends of theblades adjacent to the engaging end of the punch inwardly.

4. A centering punch provided with longitudinally extending groovesspaced apart from each'other, a centering blade arranged in each grooveand pivoted to the punch, each blade being of angular formation andpivoted at the angle thereof, and means for simultaneously swinging theblades on their and a a collar movable on the punch and embrac- 25pivotal connection, said means comprising a collar movable on the punchand embracing the blades.

5. A centering punch provided with longitudinally extending groovesspaced apart from each other, a centering blade arranged in each grooveand pivoted to the punch, each blade being of angular formation andpivoted at the angle thereof, and means for simultaneously swinging theblades on their pivotal connection.

HARRY M. WVALKER.

